Apparatus for finishing metal zipper chain

ABSTRACT

Apparatus for blunting selected edges of the metal elements of a zipper chain comprises a pair of spaced toothed gears adapted to intermesh with the opposite sides respectively of fastener elements of a zipper chain moving between them.

llnited States Patent 1191 Burbank 1 1March 13, 1973 APPARATUS FOR FINISHING METAL [56] References Cited ZIPPER CHAIN UNITED STATES PATENTS [75] Inventor Emem Burbank Middlebu' 3,548,482 12/1970 Graf ..29/207.5 y Conn- 3,482,301 l2/l969 Pcrruella. ..29/207.5

. 2,078,017 4/1937 Poux ..29/410 [73] Asslgnee. Sc0v1ll Manufacturing Company, 2,821,727 2/1958 corckranm 72/187 Waterbury, Conn- 2,251,821 8/1941 Carlile ..72 198 [22] Filed: May 7, 1971 Primary ExaminerLowell A. Larson PP 141,162 Attorney-Dallett Hoopes 52 us. c1. ..72 194, 29/410, 72/198 [57] ABSTRACT [51] Int. Cl. ..B2lh 7/00 Apparatus for blunting selected edges of the metal ele- [58] Field of Search ..72/187, 194, 19s; 29/2075, ments of a pp chain comprises a p of Spaced 29 410 toothed gears adapted to intermesh with the opposite sides respectively of fastener elements of a zipper chain moving between them.

2 Claims, 8 Drawing Figures 3o- {30 F s g 4 I v, A 7 I PATENTEBMAR 13 I975 INVENTOR John E.Bu.r);'a.nk BY ATTORNEY APPARATUS FOR FINISHING METAL ZIPPER CHAIN This invention relates to an apparatus for finishing metal zipper chain. More specifically, the invention relates to an apparatus for blunting selected edges of the metal fastening elements of the zipper chain.

In the past, objection has been registered to the sharp edges on the metal fastening elements of zipper chains. These sharp edges, which are particularly manifest when the zipper chain is flexed longitudinally, have been objected to for scratching the fingers of apparel workers and later the fingers of people operating the zippers when it is installed on apparel. The fabric surrounding the zipper has also become worn in contact with the sharp edges of metal fastener elements.

Prior attempts to smooth down or blunt the edges of metal fastening elements have usually involved the wire brushing of the finished zipper element. WHile such brushing has burnished off the extremely sharp portions of the fastener elements, it has been hard on the fabric of the zipper and indeed has often torn fastener elements away from the tape.

The present invention has for its object a simple apparatus adapted to blunt the sharp edges of zipper elements to avoid the objections of prior elements.

Other objects and features of the invention will be apparent from a review of the following specification including the drawings wherein:

FIG. 1 shows a schematic view of an apparatus embodying the invention and being used on a zipper chain;

FIG. 1a is a sectional view taken on the line la--a of FIG. 1;

FIG. lb is a sectional view taken on the line 1b-1b of FIG. 1;

FIG. is a sectional view taken on the line lc-1c of FIG. 1;

FIG. 2 is a fragmentary, greatly enlarged view showing a portion of the apparatus in operation;

FIG. 3 is a fragmentary, enlarged view of a zipper chain after being treated by an apparatus embodying the invention;

FIG. 4 is an enlarged sectional view taken in a plane including the axes of a modified form of intermeshing gears embodying the invention; and

FIG. 5 is a sectional view taken on the line 5-5 of FIG. 4.

Briefly, the apparatus of the invention comprises a pair of spaced toothed gears adapted to intermesh with the opposite sides respectively of fastener elements of a zipper chain moving between them. The gear teeth are shaped to engage and blunt the selected edges of the metal fastening elements.

Referring more specifically to the drawings, an apparatus schematically shown in FIG. 1 is designated 10. A zipper chain C having fastener elements F is drawn from a supply S through the apparatus. The apparatus comprises a pair of spur gears 12 which are so spaced that their teeth intermesh from opposite sides of the chain with the fastener elements F.

As shown in FIG.1a, the fastener elements of the chain at the time of the finishing process accomplished by the machine may be intermeshed, and the gears 12 and 12' may be staggered properly to engage both sets of elements at the same pass through the apparatus. For simplicity, the upper and lower gears are called a pair herein.

As shown in the greatly enlarged FIG. 2 view, the teeth 14 are quite shallow in depth and the bottom land 16 is narrower than the-width of each fastener. Rising from the bottom land, the flank 18 of each tooth may be planar with the land and flank planes bearing angular relationship of about 45. An effective relationship has been found anywhere in a range of 30 to 60. It should be understood, however, that the juncture of the flank 18 to the bottom land may be a fillet in contrast to a pronounced sharp intersection. Indeed, the teeth may be of a multitude of shapes provided that the bottom land 16 which is preferably flat be narrower than the width of an individual metal fastening element. It should be noted that the tooth shapes on the various gear sets as set forth are extremely simple and easy to make and maintain by ordinary grinding methods.

As the fastener elements F of the chain C move through the adjacent gears 12 (FIG. 2), it should be noted that the trailing flank 18a of a gear tooth first contacts the leading edge of the element F and that as the motion progresses, the land 16, and finally the leading flank 18b of the next tooth contacts the element. The result is a progressive engaging and compressing of the fastening-element as the fastening element is brought into the centerline position shown in FIG. 2. Further progress of the chain moves the now completed fastening element out of engagement with the gear teeth.

During the process described above, the rocking action of the teeth relative to the fastening elements F produces the blunting of the fastening-elements. In this connection, it is highly desirable that the diameter of the gears 12 be such that only a small number of fastening elements are contacted by the gears together at any one time. This sizing not only permits accommodation of the apparatus with respect to variations in the spacing of the zipper fastening elements, but also achieves the desired intense and abrupt rocking, extremely efficacious in blunting the selected edges.

The finished fastening element F (FIG. 2) is, as a result of the work of the apparatus, reshaped to include the chamfers 20 which no longer present the hazard of the former sharp element edges.

The apparatus of FIG. 1 also includes sets of gears 2424 and 26-26 which are directed at differing angles respectively to similarly work off (FIGS. 1b, 1c) the edges adjacent the heel of the fastening elements or scoops. The operation of the gear sets 24-24 and 26-26 are very comparable to those of the gear sets 12-12 of FIG. la. The gear sets 24 and 26 effect a chamfer 22 at the heel of the fastening elements as shown in FIG. 3. It should be noted, incidentally, that the intermeshing portions of the fastening elements including the engaging nibs 34 and recesses 36 of adjacent element, are in no way affected or impaired by the apparatus of the invention. For this purpose, it will be noted that the sets of gears 12 and 14', for instance, are spaced to avoid the engagement of these critical fastening member shapes.

WHile it may be that one or more of the various gear sets 12, 24 and 26 be driven to advance the chain through the apparatus, it is preferable to have independent pulling rollers 28 which are powered for that purpose.

It is also envisioned that the plurality of sets of gears 12, 24, and 26 working with companion gears 12', 24,

and 26' may be replaced by a single specially-shaped gear having a structure such as that shown in FIGS. 4 and 5. In this version, not only the sides of the fastening elements are blunted but also the heels simultaneously. The lateral thrust on one of the fastening elements due to the action of the heel-engaging portion of the gear face is countered by the opposite thrust imparted to the heel of the adjacent fastening element on the other chain by the adjacent gear. However, it should be understood that the preferred version of apparatus involves a plurality of sets of gears such as shown in FIG. 1.

In the FIG. 4 and 5 versions, the gears 12" are each formed with an end flange 30. At the outside end of the teeth, the flange member, which may be appropriately contoured to show in effect bevelled gear teeth 32 facing in toward the fastening element as will be understood, effects a blunting of the edges on the heel of the fastening elements.

Variations from the embodiment shown are possible still falling within the scope of the following claim language:

I claim:

1. Apparatus for blunting selected edges of the metal fastening elements of a zipper chain including a pair of intermeshed zipper stringers, the apparatus comprising a pair of spur gears adapted to engage in a meshing relationship, opposite sides of the row of fastening elements, respectively, the teeth being shallow in depth, the land of each tooth being substantially narrower than the width of the zipper fastening elements, the gears being ofa diameter so that only a small number of fastening elements are contacted by the gears together at any one time and a second and third pair of spur gears disposed to engage fastening elements as the first set but directly obliquely with respect to the fastening element so as to blunt selected edges at the heels of the elements, one of the spur gears of the second and third pair adapted to engage each of the four heel comers of the interrneshed fastening elements, whereby the lateral thrust imparted to the fastening elements by each of the obliquely directed spur gears of the second and third pair is countered by an equal and opposite thrust directed by the oppositely directed spur gear of the other pair.

2. Apparatus as described in claim 1 wherein there is additionally provided a set of drive gears to engage the fastening elements similar to the first set of gears, and powered to advance the chain through the apparatus. 

1. Apparatus for blunting selected edges of the metal fastening elements of a zipper chain including a pair of intermeshed zipper stringers, the apparatus comprising a pair of spur gears adapted to engage in a meshing relationship, opposite sides of the row of fastening elements, respectively, the teeth being shallow in depth, the land of each tooth being substantially narrower than the width of the zipper fastening elements, the gears being of a diameter so that only a small number of fastening elements are contacted by the gears together at any one time and a second and third pair of spur gears disposed to engage fastening elements as the first set but directly obliquely with respect to the fastening element so as to blunt selected edges at the heels of the elements, one of the spur gears of the second and third pair adapted to engage each of the four heel corners of the intermeshed fastening elements, whereby the lateral thrust imparted to the fastening elements by each of the obliquely directed spur gears of the second and third pair is countered by an equal and opposite thrust directed by the oppositely directed spur gear of the other pair.
 1. Apparatus for blunting selected edges of the metal fastening elements of a zipper chain including a pair of intermeshed zipper stringers, the apparatus comprising a pair of spur gears adapted to engage in a meshing relationship, opposite sides of the row of fastening elements, respectively, the teeth being shallow in depth, the land of each tooth being substantially narrower than the width of the zipper fastening elements, the gears being of a diameter so that only a small number of fastening elements are contacted by the gears together at any one time and a second and third pair of spur gears disposed to engage fastening elements as the first set but directly obliquely with respect to the fastening element so as to blunt selected edges at the heels of the elements, one of the spur gears of the second and third pair adapted to engage each of the four heel corners of the intermeshed fastening elements, whereby the lateral thrust imparted to the fastening elements by each of the obliquely directed spur gears of the second and third pair is countered by an equal and opposite thrust directed by the oppositely directed spur gear of the other pair. 